The present invention relates to a piezoelectric vibrator or actuator which comprises a plurality of stacked or piled piezoelectric sheets. It is known that the piezoelectric vibrator can convert electric energy into mechanical vibration or energy and can convert the mechanical vibration or energy into the electric energy.
A conventional piezoelectric vibrator comprises a plurality of stacked piezoelectric sheets each of which has an upper surface, a plurality of first-set elongated electrodes on the upper surface in parallel, and a plurality of second-set electrodes on the upper surface in parallel. Each of the second-set elongated electrodes is arranged halfway between two adjacent ones of the first-set elongated electrodes. As will later be described more in detail, the conventional piezoelectric vibrator is incapable of reliably preventing dielectric breakdown of the piezoelectric sheets.